The invention relates to comminuting machinery and, more particularly, to machines which may be referred to as grinders, wood hogs, and hammermills, or particularly disposing of waste scrap wood and the like which is comminutable or fragmentable to chips or shreds.
Machines of the general character mentioned have been provided with wedge-locked tool assemblies of a great many designs. The present invention has been developed for particularly treating scrap wood, such as beams from demolished buildings, pallets, old railroad ties, and even forestry wood. Such machinery employs tools which encounter high impact forces and sometimes foreign matter such as nails and-bolts, so that the life of the tooling is not expected to be lengthy. While the life of the tool is determined by many factors, it is axiomatic that the tooling will need to be changed periodically due to wear and possible fracture and, accordingly, the tooling must be readily removable and replaceable.
The life of the tooling is, however, also affected by the rigidity with which the tooling is held, and whether the tooling is securely held in position so that the tools of the drum are all operating in the same axial cutting plane. The wedge-lock tool holding system, which will be described, is-an improved construction over prior art devices designed to provide a longer tool life and ready and rapid replaceability.
The invention is concerned with a rotor drum made up of one or more radially projecting members driven by a drive shaft and providing a plurality of tool assembly receiving pockets over the periphery of the drum formed for reception of the improved tool assemblies, which are locked in the pockets. The tool employed in the tool assembly has an elongate shank with a cutting head thereon having a cutter tooth with a cutter edge facing in the direction of rotation of the rotor drum. The tool shank is received in the pocket to bear upon the front wall of the pocket and the shank and front wall of the pocket have inclined front walls which extend from the floor of the pocket. The wedge employed has a rear inclined surface bearing upon the rear wall of the pocket and a front wall bearing upon the tool shank and the angle of inclination of the wedge rear surface and rear wall of the pocket is such as to provide a differential inclination with the inclined front surfaces. The wedge member has a threaded opening with an elongate threaded abutment member therein having an inner end extendable to bear upon the pocket floor. The threaded member is rotatable to draw the wedge member outwardly to securely lock the tool shank when manipulated with its inner end in bearing engagement with the pocket floor.
One of the prime objects of the invention is to provide a more reliable tool or knife clamping and securement system which holds the knife securely in position and provides the necessary rigidity for this high impact tool.
Another object of the invention is to provide a rapidly releasable clamping system which permits replacement of the knives or tools when necessary to minimize production down-time.
Another object of the invention is to provide a system which enables the tooling to be set in place accurately and uniformly.
A further object of the invention is to provide a reliable wedge-locking system wherein the tool is mounted in the front of the pocket and the packing of fine wood debris in the pocket which strives to move down the front face of the pocket in prior systems is discouraged.
A further object of the invention is to provide a system wherein the tool bar is supported in the front of the pocket and protects the wedge bolt.
Other objects and advantages of the invention will become apparent with reference to the accompanying drawings and the accompanying descriptive matter.